JPA ManyToMany Join Table has all attributes as PK

Question

I\'m using Hibernate 3.3.1 and am following along in modelling this sample table structure, but I\'m having trouble creating a join table with extra attributes.

It\

Answer 1

The code below seems to generate tables as desired, I have tested it on MySQL (just the table creation, not CRUD):

@Entity
@Table(name = "orders")
public class Order {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @OneToMany(mappedBy = "orderDetailId.order")
    private List orderItems;

    //get set …..

}

@Entity
@Table(name="products")
public class Product {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @OneToMany(mappedBy = "orderDetailId.product")
    private List orderItems;   

    //get set ……
}

@Entity
@Table(name = "order_detail")
public class OrderDetail {

    @Id
    private OrderDetailId orderDetailId;

    private double price;

    @Temporal(TemporalType.TIMESTAMP)
    private Date lastUpdatedTime;

    //get set ….            
}

@Embeddable
public class OrderDetailId implements Serializable{

    private Order order;

    private Product product;

    @ManyToOne(fetch=FetchType.LAZY)
    @Access(AccessType.PROPERTY)
    public Order getOrder() {
        return order;
    }

    public void setOrder(Order order) {
        this.order = order;
    }

    @ManyToOne(fetch=FetchType.LAZY)
    @Access(AccessType.PROPERTY)
    public Product getProduct() {
        return product;
    }

    public void setProduct(Product product) {
        this.product = product;
    }

    //hash code equals override 
}

Hibernate DEBUG details as below

DEBUG: org.hibernate.tool.hbm2ddl.SchemaUpdate - create table order_detail (lastUpdatedTime datetime, price double precision not null, product_id bigint, order_id bigint, primary key (order_id, product_id)) ENGINE=InnoDB
DEBUG: org.hibernate.tool.hbm2ddl.SchemaUpdate - create table orders (id bigint not null auto_increment, primary key (id)) ENGINE=InnoDB
DEBUG: org.hibernate.tool.hbm2ddl.SchemaUpdate - create table products (id bigint not null auto_increment, primary key (id)) ENGINE=InnoDB
DEBUG: org.hibernate.tool.hbm2ddl.SchemaUpdate - alter table order_detail add index FK23AE5A622128CF91 (order_id), add constraint FK23AE5A622128CF91 foreign key (order_id) references orders (id)
DEBUG: org.hibernate.tool.hbm2ddl.SchemaUpdate - alter table order_detail add index FK23AE5A62EB201631 (product_id), add constraint FK23AE5A62EB201631 foreign key (product_id) references products (id)